


equivalent exchange.

by 95liners



Category: Fullmetal Alchemist: Brotherhood & Manga, Haikyuu!!
Genre: Blood and Injury, F/M, Gen, M/M, Mentions of Anxiety, Reincarnation, Semi-Canon Compliant, Temporary Blindness, The Promised Day (Fullmetal Alchemist: Brotherhood), of sorts, the sakuatsu and roy/riza is more implied but tagged anyways
Language: English
Status: Completed
Published: 2020-12-22
Updated: 2020-12-22
Packaged: 2021-03-10 20:01:19
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,364
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28232835
Author URL: https://archiveofourown.org/users/95liners/pseuds/95liners
Summary: For as long as Atsumu’s been alive, he’s always noticed things.Sometimes it’s the flash of red, orange, yellow that creeps in the corners of his eyes, sometimes it’s the smell of iron and the cold feeling across his fingertips.;miya atsumu has always felt there was more to him. he never expected it would manifest like this.
Relationships: Miya Atsumu & Sakusa Kiyoomi, Miya Atsumu/Sakusa Kiyoomi, Riza Hawkeye & Roy Mustang, Riza Hawkeye/Roy Mustang
Comments: 7
Kudos: 53





	equivalent exchange.

**Author's Note:**

> trigger warnings ; blood, injury, mentions of hospital, war and genocide, guns, violence. this is set during the promised day arc, mostly focusing around the battle with envy and the forced human transmutation.
> 
> hi again yall, im BACK! i just finished fmab like three days ago and have been in UTTER brainrot, as well as getting back into the sakuatsu swing of things, so why not this? i was inspired by trust me, i'm an alchemist by metisket! amazing fic, pls check it out!

(For as long as Atsumu’s been alive, he’s always _noticed_ things.

Sometimes it’s the flash of red, orange, yellow that creeps in the corners of his eyes, sometimes it’s the smell of iron and the cold feeling across his fingertips.

_Sometimes it’s the screams of too many people at night, that wakes him up sobbing and trembling in his mother’s arms-_

He’s always felt this difference, something that sets him apart from everyone else. Even Osamu doesn’t know what Atsumu’s talking about half the time, having finally grown used to the crazed rants at three in the morning, the frantic sobbing after Atsumu’s shoved from his sleep again, his eyes darting around during random periods in the day.

Atsumu doesn’t know what’s happening to him, but he knows it feels _wrong_.)

* * *

The sun warms Atsumu’s skin even as he sits inside his car, still parked underneath his apartment complex, and it feels like a normal day. He’s had his peppermint tea, he’s had his daily _get made fun of by Osamu_ FaceTime call, and he’s even had his morning shit – Atsumu feels like he’s on top of the world this morning.

Pulling out of the parking lot and driving down to the gym is a simple action, muscle memory, and it’s what keeps Atsumu going as the faint sensation of wind whips at his arm hair, before disappearing again. The sensations never last long, and there’s never too many of them. Hell, Atsumu’s gone months without noticing one before – and then there are bad days, bad weeks, bad _months_.

Bad years.

It’s the sight of Hinata bouncing around outside the gym that brings Atsumu back to Earth, pulling into a free parking spot outside and locking everything up. There’s another car parked in front, one that’s _not_ Hinata’s, and Atsumu’s given all of five seconds to remember whose it is before a familiar mop of curly, black hair appears.

“ _Omi!_ ” Sakusa bodily flinches at Atsumu’s scream, head whipping around to show wide eyes and an almost _frightened_ expression. It doesn’t stop Atsumu from grabbing his bag, slinging it over his shoulder, and marching all the way over to lean against the car and grin up at Sakusa.

“Can you _please_ leave me?” Sakusa grumbles from behind his mask, obviously put out as he eyes Atsumu’s body against his pristine, shiny car. Hinata giggles from his spot by the locked gym door, watching as Sakusa practically buries Atsumu with his glare.

“Come _on_ , Omi-Omi, we’ve got a big practice game today, you can’t be slouching around already!” Sakusa’s decidedly unimpressed by Atsumu’s whining and groaning, instead pushing past to finally meet Coach Foster at the gym door, who’s definitely giving Atsumu a weird look.

“Get into gear, Atsumu, we need you in top form in this practice game. Stop harassing your teammates.”

It’s with a put-upon sigh, and the ghost of sunshine not seen on this overcast Osaka day, that accompanies Atsumu into the gym.

* * *

_There’s a promise shared between colleagues, between friends, between the two people who have gone through hell and back together._

_There’s a promise to make it out alive, together._

* * *

“Are you alright, Atsumu?” Meian sounds worried as he looks over at the setter, who’s seemingly staring off into the distance. Inunaki’s about to get up and gently thwack Atsumu back into reality, before Sakusa simply rolls a water bottle over to him. He’s still stretching his body, making sure every single one of his freaky, flexible limbs are adequately warmed up. There’s a tenseness to his shoulders that still won’t leave no matter what, something that’s a common sight with him.

The water bottle gently thumps against Atsumu’s foot and jolts him out of his daydreams – the waft of _sewerage_ of all things had invaded his senses, and the chill of something underground buried itself into his bones. There’s a simple shake of his shoulders and Atsumu firmly sets himself back into his reality, finishing his stretches to grab his water bottle and take a big swig.

“I’m alright, captain, don’t worry about me! Worry about Bokkun,” everyone’s heads turn to face Bokuto at Atsumu’s statement, who’s currently face down on the ground groaning about some cute animal he saw on the way to the gym, “maybe he’s falling into his emo mode.”

Meian looks every bit a tired father as he waves Atsumu off and goes to deal with Bokuto, Barnes trailing behind him and leaving the others to finish their stretches and get on with preparations.

“Are you excited to play against EJP again, Omi-san?” Hinata’s calling out over his stretches, eyes firmly fixed on his feet and not Sakusa who’s meticulously rolling his wrists and warming them up.

“I think so,” is Sakusa’s final answer, and it almost floors Atsumu how polite he is. For once. “I enjoy playing against Motoya, and Suna-san is definitely interesting. I just wish to hurry up and play, that’s all.”

Hinata’s whooping and cheering at the sudden enthusiasm from MSBY’s resident ice-cold prince, but Atsumu can’t help the closer look at Sakusa – the rigidity spreading from his shoulders to the tense purse of his lips, the furrow of his eyebrows, the pallor of his skin only a shade lighter than usual …

Something’s wrong, and it finally begins to hit Atsumu.

* * *

_Gunshots and yells ring out around her, but she’s still steadfast in her actions – aiming, firing, hitting the non-lethal parts of the body._

_Taking them all out one by one. Thinning the forces._

* * *

“Ugh, Sunarin,” Suna shoots a smile full of pain and _you’re dead later_ to Atsumu, whose insides do not curl up in fear at all. He’s still on edge from earlier – it’s begun to set in, whatever’s happening. Atsumu’s felt this before, he’s felt the beginnings of this anxiety, this trepidation, and it lead into one of his worst years to date – he hopes it’s only a warning for now, a small period to pass. As long as it doesn’t throw him off his game today.

There’s only a short time before the practice game starts, with everyone catching up, stretching, preparing with their teammates before they begin. Atsumu’s sitting down to gather his thoughts, to calm his racing heart, when he notices Sakusa in the corner. Komori’s with him, and Sakusa … doesn’t look good. Not at all, but he’s shaking his head and moving over to where the rest of the Jackals are, and Komori looks frustrated.

There’s mere seconds before Komori’s gaze falls on Atsumu, and his eyes lock onto his, and Atsumu just _knows_ Komori is looking through him. Telling him to watch out for Sakusa. Telling him to stay safe.

_(But … what’s he staying safe from?)_

There’s a whistle, with Adriah dragging Atsumu over to the others, and he’s still just pulling himself from his fog.

“Get it together, Miya,” Sakusa hisses from his left side, Atsumu’s vision clearing in time for him to shoot Sakusa a betrayed look, “if you go down, we all suffer. Don’t fuck this up.”

There’s a snort from his left as Inunaki ducks his head, and Meian shakes his head as if he expected this and was still let down.

“Alright kids, listen up,” Coach Foster finally pulls them all into focus, the players and other members of the Jackals all around him, “we have the privilege of playing against EJP Raijin today, another Division One team, so I expect everyone to be on their top game, and to really _learn_ from today. We’re going to dominate the season, okay, so I expect you to do your best today and work towards that. Alright?”

There’s a resounding chorus of cheers and agreement as there’s another whistle, and Atsumu’s left behind once more, staring down at the ground in front of where Coach Foster had been before.

Why … was there blood?

“ _Atsumu!_ ” Sakusa’s hooking a hand into the curve of Atsumu’s elbow and dragging him over, and there’s something wild in his eyes, something flaring up for a second before dying down again. “Get it together, _okay_? You have to keep it together, you can’t fall apart like this in front of everyone, okay?”

Atsumu’s bristling at that absentmindedly, he feels he should be offended, but then Sakusa’s voice drops lower, and there’s something feral and desperate tinging his every word, and Atsumu feels that pit of fear inside of him grow even stronger.

“Hold it together, _Lieutenant_ -”

* * *

_There’s raging infernos, and utter hatred, and she doesn’t think she’s ever seen him this way before. This consumed by rage and revenge. It’s terrifying, and the gun is cocked and held eye level before she’s even aware of her actions._

_He said once to take him out if he steps too far. Her gun is heavy in her hand, yet is she strong enough to bear it?_

* * *

There’s an imperceptible shake as Atsumu prepares his first set, steadying his voice enough for _“Bokkun!”_ to ring out across the gym, and Bokuto delivers a mean cut shot that slams into the court. Hinata’s cheering and high fiving Meian, and Inunaki claps Bokuto on the back, and Sakusa meets Atsumu’s eyes.

_What the hell is up with him today?_ Atsumu doesn’t know if that thought is directed to himself or Sakusa, but he can see Komori eyeing them through the net, and even Suna seems to have picked up that something is wrong. Sakusa’s shaking his head slightly at Komori and nods at Atsumu, but he doesn’t walk over and congratulate him, nor does he join the others. Atsumu’s eyes draw down to where Sakusa’s hands are fidgeting at his sides, noticing his thumb and middle finger absentmindedly rubbing against each other.

As if he was snapping his fingers.

There’s not enough time to care about Sakusa’s habits as the game starts again, and Atsumu prepares himself for Hinata’s serve, which goes directly to Komori and gets set up and over, straight to Inunaki, and then one of the most intense rallies Atsumu’s ever played begins.

“‘Tsumu-san!” Hinata’s calling for the ball, and Atsumu makes sure it’s a steady and perfect set he sends flying over, and then it’s coming back and he’s setting to Bokuto, and then Inunaki’s digging a hit from Washio, and everything’s flying by his eyes so fast that it’s barely enough for Atsumu to keep his head in the game, what with the flashes he sees in his peripheral vision, or the coppery smell of blood that wafts around, or the sound of water dripping faintly even though he’s nowhere near a faucet –

Sakusa stumbles as he goes to spike the ball, but it doesn’t matter as he still slams it home and a timeout is called. He looks paler than before, and Atsumu can feel a sort of kinship to the other if he wasn’t so focused on the sudden racing of his heart, and the steadying hand of Meian Shugo on his elbow.

“Are you alright, Atsumu?” He definitely sounds worried, enough for Atsumu to paste a smile on his face and nod.

“Of course, captain!” Meian’s sighing again, but Atsumu still continues on, “’M all good! Jus’ gettin’ into the swing’a things! Sunarin messed me up before but ‘m good now!” Atsumu doesn’t say how he’s growing more and more worried about Sakusa, but the quick glance over to the other is enough for Meian to set his eyebrows into a furrow, looking over to the spiker as well.

“… You sure? You and Sakusa, you’ve both been off today,” Meian’s worries wash over Atsumu as he shakes him off, already preparing for the next set. Today’s not the best, and he can only feel that trepidation in his gut worsening, but what can he do about it? Atsumu doesn’t even know _why_ it happens, if it’s some fucked-up form of anxiety, if it’s some supernatural force messing with him.

He can’t do a damn thing about it right now.

A large hand clapping his shoulder lets Atsumu know Bokuto is there, cheering him up, and he sees Hinata and Inunaki shooting him a thumbs up. Meian’s still next to him, but he knows the younger setter is going to push through, and he should be fine.

With a glance over his shoulder to see Sakusa, Atsumu feels something solidify between them, as he watches Sakusa still snapping his fingers absentmindedly.

* * *

_They’re everywhere, and it’s so dark, it’s so cold, and she’s going to go down sooner rather than later. She didn’t want to tell him, she didn’t want to worry him, but will they win this? With the hordes of the undead running towards them, cutting them down with every slice?_

_She doesn’t want to die at the hands of this Doctor, she won’t die, not in front of him …_

… not in front of him, not in front of him, not in front of hi-

There’s a sudden _slash!_ and blood, so much blood, but nothing sprays onto the gym floors as Atsumu just …

_Drops_.

“Atsumu!” Meian’s yell is barely heard over Atsumu’s screaming, clutching his neck and curling up, frantically scrabbling to keep from bleeding out, but the blood smearing over his fingers doesn’t even stain, doesn’t drip to the floor, doesn’t _exist_ –

“Atsumu!” No one expects Sakusa to suddenly skid to Atsumu’s side, eyes wide and feral as they were before, hands hovering nervously as if he doesn’t know what to do, before Atsumu finally opens his eyes and locks with Sakusa’s and –

_Fuck_.

* * *

_Roy Mustang is not a great man. He’s the Hero of Ishval – the hero of an unnecessary genocide, killing and murdering and ruining an entire race. He’s powerful, he’s intelligent, and he’s on his way to becoming the Fuhrer._

_And he would do anything to keep Riza Hawkeye from dying in front of him, bleeding out onto the human transmutation circle in front of him._

_There’s a moment when he thinks they’ve won, when May Chang has healed Riza and she’s safe in his arms, but then he’s being manhandled and there’s swords in his hands and oh god, oh fuck oh no –_

Atsumu’s pain dulls after ten long, excruciating minutes, the game completely and utterly abandoned as he’s pulled into their locker room. Head resting on Barnes’ shoulder, Atsumu feels drained, mind scrambling with images of swords, of undead people, of a man with black hair and flames erupting and black tendrils and _screaming_ –

There’s a crash and Sakusa collapses against one of the walls, Bokuto immediately rushing over and pulling him up. There’s another wave of cries and worried noises as Sakusa barely keeps his screaming to himself, choking as his eyes roll up and his body goes limp.

There’s shocked silence for a few seconds before Coach Foster is pulling his phone out, about to dial the ambulance, and Bokuto’s laying Sakusa out on the floor, on top of the team’s jackets, and Atsumu can see two images laid over one another.

Sakusa Kiyoomi, opposite hitter of MSBY Black Jackals, inky-black curly hair spread over the floor, breathing rapid but steady.

Colonel Roy Mustang, the Flame Alchemist, pinned down by black tendrils as he’s forced into the Gateway of Truth.

Atsumu heaves out a shaking breath, eyes watering, and for a second he feels it – the long, blonde hair trailing down over his shoulders, the blood staining his jacket and shirt, the open wound crudely fixed with alkahestry.

Riza Hawkeye stares at the unconscious body of the person most dear to her.

“Fuck …”

* * *

_It’s not until the dust clears, until the entire ordeal is over, until the Elric brothers return from the Gate with Alphonse’s real body, and the Colonel is admitted into hospital, that Riza allows herself to finally feel. Process what’s just happened._

_They won. They really did, and they’re both alive._

_“Riza …?” Roy’s voice is soft, softer than she’s heard before, and it’s snapping the last thread she has in her before she’s crying quietly, so tired and so broken and so grateful._

_There’s a beat of silence before a shaky hand finds itself on her shoulder, before making its way to her head._

_“You followed orders, Riza. You stayed alive.”_

“… it’s fine, it’s over, it’s over, you’re safe –”

Atsumu comes to, only to see Komori sitting next to a shaking Sakusa, holding his shoulder and squeezing softly. It’s empty in the office of the MSBY gym – the paramedics had looked them both over, but nothing could be done.

There was nothing physically wrong with them.

Still, Sakusa was blindly reaching for his cousin in a way that concerns Atsumu, but the ache in his neck is still sore, sore enough for him to groan and fall back as he tried to sit him.

“Settle down, Lieutenant,” Komori murmurs softly, keeping his gaze on his cousin, “you’re fine, Kiyoomi, Roy, whichever’s easiest right now. You’re _safe_ , and it’ll go away soon. It will.”

“What – _Lieutenant_? _Roy_? What’s going on, Komori?” Atsumu bites down on his words as he attempts to push himself up once more, actually making it this time. “What – what are you talking about?”

“It’s happened, hasn’t it?” Atsumu has _no clue_ what Komori is talking about, but then he remembers the pain, the blood, and _oh god where is the Colonel where is Roy they took him they took him they took –_

“Atsumu,” Atsumu looks up when Sakusa calls his name, and sees him with his eyes unfocused, settling on some object of focus near him, Komori carefully tucking himself into Sakusa’s side to support him, “you – you felt it too, all day, right? The, the _fear_ and pain and – and the – the–”

Atsumu watches as Sakusa practically dissolves, shaking in his cousin’s arms and clutching tightly onto Komori like he’s a lifeline. His focus is chaotic and uncontrolled, and only then does Atsumu realise that he _can’t see_.

It’s all flashing through his mind, his vision, his body now – the Homunculi pinning Roy Mustang, Sakusa Kiyoomi, down to the ground and forcing him to open the Gateway, them disappearing, the _pain_ of being ripped from his, her, their body and put back together.

Seeing his, her, their Colonel, so thrown from his usual confidence.

“Fuck, oh my God, _Omi_ –” Atsumu scrambles forward and pulls Sakusa into his arms, Komori immediately making himself scarce. Neither Atsumu nor Sakusa hear the click of the door closing, Atsumu too busy holding Sakusa, keeping him safe as a war rages in them, with them, and they’re too helpless to do anything about it.

“It’s too much, it’s too much, I didn’t want to see it, they – they made me, they made me, _they made me_ –”

* * *

Life goes on. The war ends, and Atsumu starts to feel a peace that he’s never really felt before. He can tell that she’s happier now – Lieutenant Riza Hawkeye – and that there’s happiness wherever she is.

Sakusa’s better now, too – he’s always been like that, says Komori. Colonel Roy Mustang definitely didn’t live a peaceful and calm life, as the Hero of Ishval, and soon to be what he says is a Fuhrer.

_(Atsumu doesn’t know if he likes the sound of that.)_

His shoulders aren’t as tense anymore, and he even smiles sometimes, more than usual. Life still seems hard, Atsumu sees it every now and then: uprisings, tension, the aftermath of a broken and corrupt country.

Komori sits down and explains it all to them, explains how he knows, how he’s been watching Sakusa ever since he realised that they were the same and that he could _help_. He says he’s some confusing name, that he’s a traveller wherever these Riza Hawkeye and Roy Mustang are from, that he’s been around for too long. There’s a day where he just changes, where he doesn’t know anything of what’s going on anymore, but at that point Atsumu and Sakusa have both sensed the news, from another world entirely, that Van Hohenheim, passed away.

Still, there’s happiness now, and Sakusa looks at him more often with a different sort of gaze in his eyes.

Trust, more than a spiker has to their setter, who carries them through their games.

Like a Colonel looks to their trusted Lieutenant.

**Author's Note:**

> hit me up on [twitter](https://www.twitter.com/aIphonseIrics).
> 
> also, a HUGE thanks to [Fallen_Ace](https://archiveofourown.org/users/Fallen_Ace/pseuds/Fallen_Ace) who helped me out from the sass server to beta this! you rock you ROCKKKK


End file.
